Can I take Robitussin gel caps anally?

I know there intended to be taken orally, but I was curious if they could be taken anally, and still have the same or similar effects. I'm taking 2.5 bottles of the gel caps right now, and can reach the third plateau, but my friend always throws hers up =[ so she's always stuck at the second plateau.

So, can I take the gel caps anally? Will this be effective and safe?

If not, what about the Robitussin cough syrup? Could I take that as an enema and get the effects I'm looking for? Mind you, I'm not all that worried about having a buttplug in my bum for 8 hours Lol. I just want to know if it would be safe and effective.

Thanks! ^^